The Mediterranean is a warm Sea or Ocean between Europe and Africa. Coastal areas round the Mediterranean are popular tourist destinations. The Mediterranean is almost entirely enclosed. The Strait of Gibraltar connects it with the Atlantic Ocean, and the Suez canal connects it to the Red Sea. Many ancient civilisations developed round the Mediterranean.
Geologically the Mediterranean is an ocean though it's usually called a sea. Marine life in the Mediterranean is under threat through pollution and overfishing.  In the past few Million years the Straits have closed on at least one occasion and as a result the Mediterranean basin largely dried out. This is unlikely any time soon since Global warming causes sea levels to rise.